Definition: You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
Input: Question: Which one of the following numbers is the greatest positive integer x such that 3^x is a factor of 729^5?

 Option A: 5

 Option B: 8

 Option C: 10

 Option D: 15

 Option E: 30

Option E